Prime Lenses: One Focal Length, Many Benefits

The market today is flooded with ever-better zoom lenses built to cover practically every imaginable range. And yet there are still photographers who make do without any zoom at all. Is it really possible to stick to just one prime lens and completely forget about all the other focal lengths? What do you lose? What do you gain?

Aa prime lens is one that can’t be zoomed. So it only has one single, fixed focal length, and an unchanging angle of view derived from that.

So What?

The first question, of course, is “Why bother?” After all, you can just use a zoom lens instead and then conveniently change the frame to meet your needs. But fixed lenses have several advantages.

Their greatest benefit is that they usually have very great lens speeds. Their small depth of field also enables you to strongly blur backgrounds to emphasize your pictures’ subjects. They also enable you to take pictures even in poor light conditions, because prime lenses get more out of the ambient light.

A Bedouin in a dark desert night under candlelight. A tough challenge even for a fast lens. Canon 40D, Canon EF 85/1.8, 1/10 s, f/1.8, ISO 3200, focal length 85 mm
A Bedouin in a dark desert night under candlelight. A tough challenge even for a fast lens.
Canon 40D, Canon EF 85/1.8, 1/10 s, f/1.8, ISO 3200, focal length 85 mm

Prime lenses are also easier to build, and so they’re usually lighter than similar zooms, while also having better optics.

It’s probably no coincidence that there are DSLRs and mirrorless cameras on the market with prime lenses that can’t even be changed out. These are cameras that will only ever experience one lens in their entire lives. And despite this, or even because of it, they’re a market success. The Fujifilm X100 (now superseded by the X100T) is a good example of this, and so is the Sony DSC-RX1 (now superseded by the DSC-RX1R II).

The Ideal Focal Length

Some focal lenses are more universal, some more specialized.  The 50 mm focal length is most similar to human vision. (Note: all focal lengths I’m mentioning here are meant as full-frame/35mm equivalents.)

Even though this is still a “crop” relative to human vision, when you print out a 50mm image and put it on your wall, looking at it should give you the feeling that you’re standing right in the scene.

A model on a bridge, captured using a standard 50mm lens. Canon 5D Mark III, Sigma 50/1.4 DG, 1/50 s, f/1.4, ISO 200, focal length 50 mm
A model on a bridge, captured using a standard 50mm lens.
Canon 5D Mark III, Sigma 50/1.4 DG, 1/50 s, f/1.4, ISO 200, focal length 50 mm

This is what has made 50 mm a standard focal length found in the catalog of perhaps every single camera maker. Even just counting Canon lenses, you’ll find three prime fifties: an f/1.8, an f/1.4, and an f/1.2. Meanwhile, this focal length was also used by famous photographers of the past, such as Henri Cartier-Bresson.

You can also use this lens to quite successfully shoot a wide range of genres—everything from portraits to larger looks at events around you.

But keep in mind that this lens can’t go very wide, so any kind of wide landscape won’t fit into the frame, nor will an interior, unless it lets you step back.

A landscape seen through a 50mm lens. Canon 5D Mark III, Sigma 50/1.4 DG, 1/1600 s, f/1.4, ISO 100, focal length 50 mm
A landscape seen through a 50mm lens.
Canon 5D Mark III, Sigma 50/1.4 DG, 1/1600 s, f/1.4, ISO 100, focal length 50 mm

So if I personally had to choose just one focal length and forget about all the others, I would probably go for another standard—35 mm. This choice is in line with the fact that the phenomenon of prime, interchangeable lenses that I mentioned actually revolves mainly around 28mm and 35mm lenses.

Working With a prime Lens

No matter what kind of prime lens you have, prime-lens work is fantastic practice from which you’ll learn a lot as a photographer. I often head out to shoot with just a prime lens and leave all my zooms at home, just for the practice.

The first effect of using it—and it’s one you’ll encounter immediately—is that you’ll start to get a better idea of what will or won’t fit into the frame. It’s said that when you’re using prime lenses, you “zoom with your legs,” and that’s the truth. But precisely because this lens improves your feel for the frame, you’ll be able to instinctively take those few steps forward or back even before you lift the camera. So using a prime lens is not as awkward as it might at first seem.

Also, if you can’t change your position, or your current composition is better than the alternatives, there’s always the option of cropping to simulate a longer focal length. While this comes at the cost of reduced resolution, most cameras today already have more resolution than you need, so you can afford it.

Prime lenses are typically sharper than zoom lenses, so even a smallish crop will be usable without problems. When the pictures will only be used at a web resolution, then even strong cropping is fine.

While this is an extreme example, it shows the kinds of options you have when cropping pictures for the web. The original photo was taken with a 50mm lens; the crop corresponds to a focal length of about 350 mm. Canon 5D Mark III, Sigma 50/1.4 DG, 1/1600 s, f/1.4, ISO 100, focal length 50 mm
While this is an extreme example, it shows the kinds of options you have when cropping pictures for the web. The original photo was taken with a 50mm lens; the crop corresponds to a focal length of about 350 mm.
Canon 5D Mark III, Sigma 50/1.4 DG, 1/1600 s, f/1.4, ISO 100, focal length 50 mm

The real problem comes in the opposite situation, where you want to capture a wider angle than your current lens can enable. Either you have to satisfy yourself with a crop or some other compromise, or you have no choice but to create a mini-panorama (it can even just be stitched from two pictures) If you have enough time and patience, then use can use what’s called the “Brenizer Method” to get a panorama that looks better than a wide-angle original.

A panorama taken using the Brenizer Method. I took a total of 35 source photos with an 85/1.8 lens.
A panorama taken using the Brenizer Method. I took a total of 35 source photos with an 85/1.8 lens.

What to Expect From a Prime Lens

At first you won’t be getting the pictures you originally expected. Being tied to one focal length simply will restrict you. But there’s not just one way to photograph a scene! If it doesn’t work in precisely one way, it will work another way. So this restriction forces you to be creative, and it may open up your eyes. If you overcome your initial fear, you can soon boast about how little gear you need to take a picture.

Below is an example of a bridge photographed using 29mm and 85mm focal lengths. A different photo each time, but they’re both fine. Looking at one doesn’t push you to think about how the scene could be captured in the other way.

A bridge shot with a 29mm focal length Canon 5D Mark III, Canon EF 16-35/2.8 II, 1/20 s, f/9, ISO 800, focal length 29 mm
A bridge shot with a 29mm focal length
Canon 5D Mark III, Canon EF 16-35/2.8 II, 1/20 s, f/9, ISO 800, focal length 29 mm
An illustrative photo that can be used to supplement other more important ones. Canon 5D Mark III, Canon EF 85/1.8, 1/100 s, f/1.8, ISO 320, focal length 85 mm
An illustrative photo that can be used to supplement other more important ones.
Canon 5D Mark III, Canon EF 85/1.8, 1/100 s, f/1.8, ISO 320, focal length 85 mm

Not having to tote a heavy zoom lens, or worse yet a set of them, is also liberating. Thanks to this you’ll be able to take your camera to more places than usual.

Your photos from a single event will also feel more unified, which can be an advantage—or a disadvantage. In any case the absence of multiple focal lengths means that your pictures will be stylistically similar and will all be a good fit for each other. But to keep the result from being boring, you’ll want to try to capture a variety of objects and use a variety of compositions. Otherwise, you can end up with, for example, nothing but a series of headshot portraits, all in golden crops.

An illustrative photo that can be used to supplement other more important ones. Canon 5D Mark III, Sigma 50/1.4 Art, 1/3200 s, f/1.4, ISO 100, focal length 50 mm
An illustrative photo that can be used to supplement other more important ones.
Canon 5D Mark III, Sigma 50/1.4 Art, 1/3200 s, f/1.4, ISO 100, focal length 50 mm

My Experience With Prime Lenses

My approach is to take a single prime lens and go on short walks or do other activities where I know what to expect, and I’m heading out not just for the fun of it, but to take pictures.

For important situations such as commercial orders or trips lasting a week or longer, I usually have two lenses (sometimes even more) depending on the situation.

My second lens enabled me to capture the scene differently, giving me more varied pictures. And if I’m on commercial orders, I’m glad to have a backup lens, in case something happens to my main lens. While I know it will be a restriction, thanks to my experience with using a single lens, I can expect that I’ll manage with my second lens too.

For illustration: e.g. when photographing weddings I carry a 50/1.4 lens—that’s my main one—and alongside it a 16–35/2.8 lens for capturing much wider angles. In an emergency, where one of them is damaged, I can continue with the other one. (Or not. I also have a “box of last resort” with a creaky old Macro Revuenon 24/4 wide-angle lens with an M42 mount and manual focus.)

For longer trips, where I can only hope I won’t damage something, I carry that ultra-wide-angle 16–35/2.8, plus another lens based on the situation—often an 85/1.8. That gives me the ability to shoot both wide-angle pictures and close-ups, or landscapes at the horizon.

Try It First

If you haven’t yet tried shooting with a single focal length and you have a good opportunity to do so, definitely take it. Set things up to use this setup for one day, and don’t use anything else the whole day. You’ll gain a lot of experience. And who knows—maybe you’ll catch the bug and find a new entertaining challenge for your photography.